“ Samsara refers to the process of passing from one body to another throughout all species of life. Hindus believe that consciousness is present in all life forms, even fish and plants.
“However, though the soul is present in all species, its potential is exhibited to different degrees. In aquatics and plants it is most “covered”, practically asleep, whereas in humans it is most alert. This progression of consciousness is manifest throughout six broad “classes of life, “namely (1) aquatics, (2) plants, (3) reptiles and insects, (4) birds, (5) animals and (6) humans, including the residents of heaven. Most Hindus consider samsara essentially painful, a cycle of four recurring problems: birth, disease, old-age, and death.”
See an example of a wandering soul:
